10/3/2013 2:30 PM PDT

Olympic hurdler Lashinda Demus -- who won a silver medal at the 2012 Olympics -- says her husband tried to strangle her and threatened to kill her ... and she's now desperate for protection ... TMZ has learned.

Demus just got a temporary restraining order against her husband, Jamel Mayrant -- who was arrested and jailed a couple of weeks ago for domestic violence. She claims the attack left her with bruises and a lump on her head.

The restraining order also protects their twin 6-year-old boys and her parents -- because she claims he threatened all of them as well.

Demus also claims her husband is trashing her and damaging her career, saying in court docs, "I'm a professional athlete ... so I need no derogatory emails, pictures, texts, phone calls released about me on the web or to other people."

The restraining order requires Jamel to stay 100 yards away from Lashinda, the kids and her parents.